Crossrail

Topcon's Measuring Stations MS are chosen for London tunneling project

Londonis one of the world's most popular destinations. The number of people visiting or working in England’s capital city is incalculable and the existing transportation networks have long been identified as requiring a major overhaul to keep up with the number of people.

The 2012 Summer Olympic Games spotlighted further the need for additional transportation needs and two separate projects were implemented to aid in relieving the pressure on the system – Thameslink 2000 and Crossrail.

Thameslink 2000 was originally proposed in 1991 to upgrade transport-links between the north and south of London; The Crossrail project, approved in 2007, has a longer history and was first discussed as a project more than 60 years ago. The final Crossrail project proposals include ambitious plans to create a new railway line running from Maidenhead, 50km to the west of central London, and including a connection at Heathrow Airport.
Several spur lines spread out in various directions, all aimed at efficiently moving human traffic into and out of London center.

The massive project required extensive tunneling to take place beneath the city itself. In fact, much of the route is underground, with around 42km of new tunnels beneath central London. This task is made more difficult thanks to both London’s geology and the complex array of tunnels that already exist beneath London. In addition, when finally completed, there will be eight new subterraneanstations constructed along the tunnel’s route which will also offer links into London’s underground network.

For the project to be successful, and to maintain total integrity of London’s landscape, extensive monitoring of the works would obviously be required. Morgan Sindall, part of the BBMV partnership (including Balfour Beatty, ALPINE BeMo Tunneling and Vinci Construction) tasked with the main construction project, selected 105 Topcon MS05AX high precision robotic total stations to fulfill the task. This order, placed through UK distributor ESS Safeforce is thought to be the largest ever order of 0.5second instruments from any manufacturer.

Alastair Cruickshank, engineering survey manager at Morgan Sindall, said, “We are very impressed with the Topcon MS05AX total stations supplied to us through ESS.

The quality and performance of the instruments is extremely impressive. The instruments always lock-on to the correct prism to be measured, even in challenging environments such as tunnels where there may be several prisms in the field of view of the instrument. The Matrix Detection function to automatically find and measure prisms has also saved us a lot of time.” He said, “We are positive that we made the right choice in choosing this innovative instrument from Topcon.” Matrix Detection is Topcon’s latest technological feature designed to save time and increase efficiency whilstsetting up complex arrays of prisms for monitoring systems. Using intelligent algorithms and high accuracy imaging sensors, the MS05AX is able to detect and locate all established prisms, even in low light or dark conditions.

Once located, the MS05AX then measures the prisms quickly and reliably, virtually eliminating any sources of human error. Work on the project commenced in May 2009 and it is expected that the first trains will be running on the completed system by 2018, and should soon be up to full peak time capacity of 24 trains per hour, allowinzourney times across London to be cut dramatically.